DESCRIPTION: This application from the UCSF, is one of eight coordinated applications to support a multi-center clinical trial which will investigate the efficacy of 31-P MRS in predicting and evaluating tumor response to therapy. Although, each of the eight participating institutions will perform their own independent research, the same data acquisition and analysis procedures will be used in all institutions so that comparable, reproducible results are obtained. Each institution will submit the results of their sequential studies on patients with either sarcomas, breast tumors, non- Hodgkins lymphomas or head and neck carcinomas for central statistical analyses. The hypotheses being tested are that pre-treatment pH and T2 can predict of treatment effectiveness and that early changes in 31-P metabolites indicate response to therapy. These hypotheses are based upon preliminary data from numerous research studies. The patients being considered at UCSF have squamous cell carcinoma of the head and neck. Twenty patients per year will be recruited from individuals who are already participating in the multi- center trials RTOG 88-17, RTOG 90-03 or RTOG 91-11. The treatments being compared are combinations of different types of fractionated radiotherapy with, in some cases, additional chemotherapy. MRI and proton decoupled 3 D 31-P localized MRS examinations, will be used to characterize metastatic lymph nodes of the neck pre-treatment, at 2, 8 and 20 days after the start of radiation therapy and at the end of therapy. These will determine whether the 31-P data are able to predict the effectiveness of the radiation therapy, detect lack of response at an early stage or guide in deciding if post- irradiation node dissection is required. MRI and dynamic studies of Gadolinium uptake will also be performed pre-treatment, at the end of radiation therapy and at subsequent 3 monthly follow-ups. These studies will provide pilot data to investigate the hypothesis that changes in rate of Gadolinium uptake may assist in distinguishing active or recurrent tumor from necrosis. If this is the case, MRI follow-up may prove effective in detecting early recurrence. The results of this and the overall analysis of 31-P MRS data will provide valuable information which could have a major impact on the management of patients with a wide variety of different cancers.